Lake San Antonio 11/25/2000

Much a'Dew to See Somethin'

by Steve Sergeant


Prior experience had taught me that anytime there was enough dew to warrant the use of dew heaters, blowers, and so on, the conditions wouldn't be worthwhile observing under. Last night I experienced conditions that contradict that theory.

I arrived at the overflow lot at Lake San Antonio a little under an hour after sunset. Clouds passed overhead while I was getting my 'scope set up, and changing into warmer clothes. With 20% sections of the sky obscured for tens of minutes at a time, I took my time setting up, thinking it might be an exercise in futility.

I was set up toward one end between Mark Wagner and Jim Bartolini. Down the row were Bob C., Marsha, Jim Turley, Albert H., Jamie Dillion with Liam, and on the end was Nilesh. Jim Turley declared the temperature at 38 degrees and the humidity at 86%.

By 7:00 PM, I was starting to do polar alignment on Zephram, my 12.5" F4.5 equatorial Newtonian, and the sky was looking almost as dark and as clear as I had remembered it from Calstar.

Perhaps the eastern horizon is where the less familiar stuff is (having forgotten it over the past year), or perhaps conditions were actually better in that direction. For whatever reason, it appeared that all of us were working the east to northeast between Auriga and Cetus.

I started out, as a warm-up, looking at M31, M32, & M101 in a single 1 degree 50' view of my 55mm eyepiece. The sky was plenty dark to see the dust lanes way out beyond 2 degrees from the core. I noticed several brighter points that may have been clusters or nebulous regions within M31.

That was easy in this dark site, I thought, lets see what detail I can see in M33. Clear pinwheel dust lanes to the north. Half-a-dozen bright spots that I thought must be foreground stars (but Burham's says otherwise).

Frustrated that I couldn't find them with binoculars at Montebello last Wednesday, I chased down M2 in Aquarius and M15 in Pagasus with Zephram. Vengeance is mine -- aperture wins! Good globular clusters are always fun to find.

With occasional tea and snack breaks enforced by clouds reducing clarity significantly, I started a more methodical see-what-I-could-see program to the east:

NGC2419: Intergalactic Wanderer

A mag 10.4, 4' diameter globular cluster on the south edge of Lynx.

IC405: The Flaming Star Nebula

A diffuse nebula in Auriga, the O-III filter didn't help me see it much better. It looked like a bright star on one end of a veil-like supernova remnant.

I hopped along M38, M36, M37 & M35 while I was in the neighborhood. During another fuzzy cloud-passing, I wandered over to Jim Turley's C8 to watch the transit of Ganymede across Jupiter through his bino-viewer. Even through the cloud, it was a satisfyingly sharp view of the dark shadow and trailing moon.

Back at my 'scope, I started trying to hop to M1, but I was running into problems. The temperature was down to 34 degrees with 97% humidity. I couldn't put my face up to my eyepieces without them fogging up, even when I held my breath. Worse, both my finder objective and my secondary mirror were fogging as well.

Thanks to Jim Turley again, who saved the day with a big portable battery and an Orion blower/dryer. As the night wen on, I became more and more dependent on this tool, and yet the sky was wonderfully clear and steady except for an occasional passing cloud.

Jim talked me into chasing down a couple of more difficult objects in Gemini:

IC443

This diffuse nebula right next to Propus was something that Mark Wagner challenged us to find. He didn't think it would be visible, because he had looked for it in the past. But we found it, right where Unanometria and Starry Night said it would be. In my 12", it was a just-visible arc-shaped brightening with no structure. Mark then chased it down and in his 18", and it revealed some strand-like structure.

NGC2392 Clown Nebula

This 0.7' diameter planetary nebula is a real showpiece object east of Wasat in Gemini. At 238X (6mm) it revealed a number of separate concentric zones of brightness. It had an overall bluish hue.

I fought another brief skirmish with dew. The temperature was down to 32F at this point, with the humidity still hovering at 97%. I was having to blow the dew off my eyepieces after every view, and off the secondary and finder scope after every move.

Getting tired of the dew battle, I chased some easier stuff for a while:

NGC2264 The Christmas Tree Cluster

This open cluster in Monoceros is aptly named. The brightest star is at the base of the trunk of the tree. This is a fun object.

M42/M43 Orion Nebula

I was in the neighborhood -- who can pass this one up?

With Ursa Major rising, and Bob C. challenged us to find some other galaxies that are in the field along with M81 & M82. The one he was talking about was magnitude 10.6 NGC3077. For bonus points, I also got NGC2976 at magnitude 10.8.

The temperature continued to drop to 28 degrees, and the humidity still held at 97%. The dew was turning to ice quickly. The red filter over my computer screen developed a layer of frost. Frost was also forming on my finder scope.

Making another frustrated pass with Jim's dew remover, I had one object I wanted to study more carefully before I gave up for the night:

IC2438 (Planetary Nebula)

The open cluster M46 in Puppis is spectacular enough in it's own right. But something that I'd missed on my visits to it with my Short-tube 80, and on my first visit with my 12.5", was that there's a cute ring nebula in the north west corner of it. That ring nebula is IC2438. Pushing the magnification up to 238X, I was able to make out that it is a hollow ring like the more famous M57, and the central star is quite visible.

With ice on everything, I'd had it with the dew. The only others still observing were Wagner and Bartolini. I started to tear down and pack-up. The temperature was down to 26 degrees, and the humidity was still 97%. Everything had a layer of frost on it.

After several hours nap, I drove home about 4:30. The mighty Orion, with his shimmering sword of interstellar gas hanging from his belt, accompanied me out my driver's side window all of the way to Salinas. With many brief glimpses of him along the empty road, I could see the other, more faint asterisms that must have added to the ancients interpretation of his likeness. Standing right atop the western horizon, he could well have been the most spectacular sight of the night.